Method for manufacturing light-emitting device

ABSTRACT

To provide a method for manufacturing a lightweight light-emitting device having a light-emitting region on a curved surface. The light-emitting region is provided on a curved surface in such a manner that a light-emitting element is formed on a flexible substrate supported in a plate-like shape and the flexible substrate deforms or returns.

This application is a continuation of U.S. application Ser. No.16/438,881, filed on Jun. 12, 2019 which is a continuation of U.S.application Ser. No. 15/357,636, filed on Nov. 21, 2016 (now U.S. Pat.No. 10,325,100 issued Jun. 18, 2019) which is a continuation of U.S.application Ser. No. 13/960,998, filed on Aug. 7, 2013 (now U.S. Pat.No. 9,508,961 issued Nov. 29, 2016) which are all incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a method for manufacturing alight-emitting device, and in particular relates to a method formanufacturing a light-emitting device having a light-emitting region ona curved surface.

BACKGROUND ART

A light-emitting device in which an electroluminescence light-emittingelement (also referred to as EL element) is provided on an inner surfaceof a substrate having moisture impermeability, which is molded into acurved shape in advance, has been known (see Patent Document 1).

Further, a method for manufacturing a light-emitting device by formingan organic EL element over a flexible substrate which is attached to aflat plate which can be separated, separating the flexible substratefrom the flat plate, and curving the flexible substrate along a shape ofa container or the like has been known (see Patent Document 2).

Furthermore, a light-emitting device in which a flexible EL elementsheet is interposed between internal and external shape-holding plateswhere a curved surface portion is formed has been known (see PatentDocument 3).

REFERENCE Patent Document

-   [Patent Document 1] Japanese Published Patent Application No.    2003-264084-   [Patent Document 2] Japanese Published Patent Application No.    2000-311781-   [Patent Document 3] Japanese Published Patent Application No.    2006-39471

DISCLOSURE OF INVENTION

An organic EL element includes a layer containing a light-emittingorganic compound between a pair of electrodes. The thickness of thelayer containing a light-emitting organic compound is as extremely smallas approximately several tens of nanometers to several hundreds ofnanometers. When the thickness is uneven, a defect of luminanceunevenness or a short circuit between a pair of electrodes, or the likeoccurs in some cases.

Accordingly, a processing technique for forming the layer containing alight-emitting organic compound so that the above-described defect doesnot occur has been required in the case of forming an organic EL elementhaving a curved shape on an inner surface of a substrate having moistureimpermeability, which is molded into a curved shape in advance.

Further, an organic EL element having elasticity with which the organicEL element returns to a plate-like shape cannot be curved in accordancewith a shape of a housing of a device having a complex curved surface(e.g., a curved surface where the curvature radius changes) in somecases.

When the method in which a flexible organic EL element is interposedbetween two shape-holding plates and curved is used, although theflexible organic EL element can be curved in accordance with a complexcurved surface, the weight or cost is increased because the twoshape-holding plates are used.

An embodiment of the present invention is made in view of the foregoingtechnical background. Accordingly, an object is to provide a method formanufacturing a lightweight light-emitting device having alight-emitting region on a curved surface.

In order to achieve the above object, an embodiment of the presentinvention is made with a focus on a method for forming a light-emittingregion on a curved surface in such a manner that a light-emittingelement is formed on a flexible substrate supported in a flat plate-likeshape and the flexible substrate deforms or returns. This leads to amethod for manufacturing a light-emitting device having a structureexemplified in this specification.

One embodiment of the present invention is a method for manufacturing alight-emitting device having a light-emitting region on a curvedsurface, including a first step of preparing a flexible substrateprovided with a desired curved surface in advance; a second step offorming a light-emitting element which includes a layer containing alight-emitting organic compound between a pair of electrodes so as to bein contact with the flexible substrate supported in a flat plate-likeshape; and a third step of deformation or return of a portion of theflexible substrate where a light-emitting region of the light-emittingelement is provided into a shape having a curved surface.

The method for manufacturing a light-emitting device which is oneembodiment of the present invention includes a step of forming alight-emitting element on a flexible substrate which is provided with adesired curved surface in advance and supported in a flat plate-likeshape and a step of providing a light-emitting region on a curvedsurface in such a manner that part of the flexible substrate where thelight-emitting element is provided is deformed or returned into a shapehaving a curved surface. Thus, the light-emitting region of thelight-emitting element can be provided on a curved surface without usinga shape-holding plate or the like and without another member being incontact with the light-emitting element for the deformation. As aresult, a method for manufacturing a lightweight light-emitting devicehaving a light-emitting region on a curved surface can be provided.

Another embodiment of the present invention is a method formanufacturing a light-emitting device having a light-emitting region ona curved surface, including a first step of forming a light-emittingelement which includes a layer containing a light-emitting organiccompound between a pair of electrodes so as to be in contact with afirst substrate which is flexible and supported in a flat plate-likeshape; a second step of providing, at a first temperature T1, a secondsubstrate having a heat shrink property on a surface side of the firstsubstrate where the light-emitting element is not formed; and a thirdstep of providing the light-emitting region of the light-emittingelement on a curved surface by heating the second substrate to a secondtemperature T2.

The method for manufacturing a light-emitting device of the aboveembodiment of the present invention includes a step of forming alight-emitting element on a first substrate which is flexible and issupported in a flat plate-like shape and a step of providing thelight-emitting region on a curved surface in such a manner that thesecond substrate having a heat shrink property is attached to the firstsubstrate which is flexible and the attached second substrate having aheat shrink property is deformed. Thus, the light-emitting region of thelight-emitting element can be provided on a curved surface without usinga shape-holding plate or the like and without another member being incontact with the light-emitting element. As a result, a method formanufacturing a lightweight light-emitting device having alight-emitting region on a curved surface can be provided.

Another embodiment of the present invention is a method formanufacturing a light-emitting device having a light-emitting region ona curved surface, including a first step of forming a light-emittingelement which includes a layer containing a light-emitting organiccompound between a pair of electrodes so as to be in contact with afirst substrate which is flexible and supported in a flat plate-likeshape; a second step of providing, at a first temperature T1, a secondsubstrate having a heat shrink property on a surface side of the firstsubstrate where the light-emitting element is formed; and a third stepof providing the light-emitting region of the light-emitting element ona curved surface by heating the second substrate to a second temperatureT2.

The method for manufacturing a light-emitting device of the aboveembodiment of the present invention includes a step of forming thelight-emitting element on the first substrate which is flexible andsupported in a flat plate-like shape and a step of providing thelight-emitting region on a curved surface in such a manner that thesecond substrate having a heat shrink property is attached to the firstsubstrate which is flexible and the attached second substrate having aheat shrink property is deformed. Thus, the light-emitting region of thelight-emitting element can be provided on a curved surface without usinga shape-holding plate or the like and without another member being incontact with the light-emitting element. As a result, a method formanufacturing a lightweight light-emitting device having alight-emitting region on a curved surface can be provided.

Note that in this specification, an “EL layer” refers to a layerprovided between a pair of electrodes in a light-emitting element. Thus,a light-emitting layer containing an organic compound that is alight-emitting substance which is interposed between electrodes is anembodiment of the EL layer.

In this specification, in the case where a substance A is dispersed in amatrix formed using a substance B, the substance B forming the matrix isreferred to as a host material, and the substance A dispersed in thematrix is referred to as a guest material. Note that the substance A andthe substance B may each be a single substance or a mixture of two ormore kinds of substances.

Note that a light-emitting device in this specification means an imagedisplay device or a light source (including a lighting device). Inaddition, the light-emitting device includes any of the followingmodules in its category: a module in which a connector such as aflexible printed circuit (FPC) or a tape carrier package (TCP) isattached to a light-emitting device; a module having a TCP provided witha printed wiring board at the end thereof; and a module having anintegrated circuit (IC) directly mounted over a substrate over which alight-emitting element is formed by a chip on glass (COG) method.

According to an embodiment of the present invention, a method formanufacturing a lightweight light-emitting device having alight-emitting region on a curved surface can be provided.

BRIEF DESCRIPTION OF DRAWINGS

In the accompanying drawings:

FIG. 1 is a flowchart showing a method for manufacturing alight-emitting device of one embodiment of the present invention;

FIGS. 2A to 2D are diagrams illustrating a method for manufacturing alight-emitting device of one embodiment of the present invention;

FIG. 3 is a flow chart showing a method for manufacturing alight-emitting device of one embodiment of the present invention;

FIGS. 4A to 4E are diagrams illustrating methods for manufacturing alight-emitting device of one embodiment of the present invention;

FIG. 5 is a flow chart showing a method for manufacturing alight-emitting device of one embodiment of the present invention;

FIGS. 6A to 6E are diagrams illustrating methods for manufacturing alight-emitting device of one embodiment of the present invention;

FIG. 7 is a diagram illustrating a housing where a light-emitting deviceof one embodiment of the present invention is stored;

FIGS. 8A to 8E are diagrams each illustrating a light-emitting elementthat can be applied to a light-emitting device in one embodiment of thepresent invention; and

FIGS. 9A to 9E are diagrams illustrating electronic devices and lightingdevices each of which includes a light-emitting device of one embodimentof the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are described with reference to theaccompanying drawings. Note that the present invention is not limited tothe following description, and it will be easily understood by thoseskilled in the art that various changes and modifications can be madewithout departing from the spirit and scope of the present invention.Therefore, the present invention should not be construed as beinglimited to the description in the following embodiments. Note that inthe structures of the present invention described below, the sameportions or portions having similar functions are denoted by the samereference numerals in different drawings, and description of suchportions is not repeated.

Embodiment 1

In this embodiment, a method for manufacturing a light-emitting deviceof one embodiment of the present invention is described with referenceto FIG. 1 and FIGS. 2A to 2D. FIG. 1 illustrates a flowchart showing amethod for manufacturing a light-emitting device of one embodiment ofthe present invention, and FIGS. 2A to 2D are schematic views eachillustrating a structure of the light-emitting device in a manufacturingstep.

A method for manufacturing a light-emitting device 100 having alight-emitting region on a curved surface, which is exemplified in thisembodiment, is as follows.

In a first step, a flexible substrate 110 provided with a desired curvedsurface in advance is prepared (see (i1) in FIG. 1 and FIG. 2A).

In a second step, a light-emitting element 130 which includes a layercontaining a light-emitting organic compound between a pair ofelectrodes is formed in contact with the flexible substrate 110supported in a flat plate-like shape (see (i2) and (i3) in FIG. 1 , FIG.2B, and FIG. 2C).

In a third step, the flexible substrate 110 deforms or returns into ashape having a curved surface, whereby a light-emitting region of thelight-emitting element 130 in the light-emitting device 100 is providedon a curved surface (see (i4) in FIG. 1 and FIG. 2D).

Note that a substrate supporting unit 10 supports the flexible substrate110 in a flat plate-like shape.

The method for manufacturing a light-emitting device exemplified in thisembodiment includes a step of forming the light-emitting element 130 onthe flexible substrate 110 which is provided with a desired curvedsurface in advance and supported in a flat plate-like shape and a stepof providing the light-emitting region on a curved surface in such amanner that the flexible substrate 110 deforms or returns into a shapehaving a curved surface. Thus, the light-emitting region of thelight-emitting element 130 can be provided on a curved surface withoutusing a shape-holding plate or the like and without another member beingin contact with the light-emitting element 130 for the deformation. As aresult, a method for manufacturing the lightweight light-emitting device100 having a light-emitting region on a curved surface can be provided.

Structures of the flexible substrate 110 which spontaneously deforms orreturns into a shape having a curved surface and the substratesupporting unit 10 which fixes the flexible substrate 110 in a flatplate-like shape, which can be used for the method for manufacturing alight-emitting device of one embodiment of the present invention, aredescribed.

Substrate Which Spontaneously Deforms or Returns Into a Shape Having aCurved Surface

In a step of forming the light-emitting element 130, the flexiblesubstrate 110 exemplified in this embodiment is supported in a flatplate-like shape by the substrate supporting unit 10, and in a laterstep, the substrate supporting unit 10 is released from the flexiblesubstrate 110, whereby the flexible substrate 110 returns into a shapehaving a curved surface.

As the flexible substrate 110 which spontaneously deforms or returnsinto a shape having a curved surface, for example, a metal plate or aplastic plate which was subjected to a molding process so as to have acurved surface, a plate-like composite material, or the like can begiven.

As a specific example of a metal plate, a metal plate having elasticitycan be given in addition to a material of a plate spring, such as springsteel, stainless steel, brass, albata, phosphor bronze, or berylliumbronze.

As a specific example of a plastic plate, a plate formed with any of avariety of engineering plastic, or the like can be given in addition toan acrylic plate, a polycarbonate plate, or the like.

As a plate-like composite material, a composite material of a glassfiber and a resin, a stacked material of a metal plate or a plasticplate and another material, or the like can be given.

Note that the flexible substrate 110 may include another material suchas an extremely thin glass plate (e.g. a glass plate with a thickness ofseveral tens of micrometers) or a film which prevents an impurity (e.g.water or oxygen) from passing therethrough (e.g. an inorganic materialfilm, specifically, a silicon oxide film, a silicon nitride film, or thelike).

Further, in the case where light emitted from the light-emitting element130 is extracted to the flexible substrate 110 side, a material having avisible-light-transmitting property is used for the flexible substrate110 and an electrode of the light-emitting element 130 which is placedon the flexible substrate 110 side.

The curved surface of the flexible substrate 110 can be deformed into aflat plate-like shape. Further, the flexible substrate 110 deformed intoa flat plate-like shape can return into a shape having a curved surface.Such a curved surface can be referred to as “developable surface”. Adevelopable surface means a curved surface through a given point ofwhich at least one straight line can be drawn.

Note that the thickness of the flexible substrate 110 and the curvatureradius of the curved surface of the flexible substrate 110 may depend ona structure of a light-emitting element which is to be formed thereon.For example, when the thickness of the flexible substrate 110 is greaterthan or equal to 40 μm and less than or equal to 300 μm and thecurvature radius is greater than or equal to 20 mm, a defect in whichthe light-emitting element 130 is damaged when the flexible substrate110 returns into a shape having a curved surface can be prevented.

Substrate Supporting Unit

The substrate supporting unit 10 supports the flexible substrate 110which spontaneously deforms or returns into a shape having a curvedsurface so that the flexible substrate 110 has a flat plate-like shape.FIG. 2A schematically illustrates a state where the flexible substrate110 molded into a convex shape upward in advance is prepared in a flatplate-like shape by being supported by the substrate supporting unit 10along its surface. Alternatively, a substrate molded into a convex shapedownward in advance can be prepared in a flat plate-like shape by beingsupported by the substrate supporting unit 10 along its surface.

The flexible substrate 110 may be supported in a flat plate-like shapealong the surface of the substrate supporting unit 10 in such a mannerthat edge portions of the flexible substrate 110 are held by, forexample, a clamping unit.

Alternatively, a magnetic force may be used. The flexible substrate 110is drawn using a magnetic force along the surface of the substratesupporting unit 10. Further alternatively, the flexible substrate 110may be supported in a flat plate-like shape in such a manner that afixture is drawn to the surface of the substrate supporting unit 10 by amagnetic force and the flexible substrate 110 is interposed between thefixture and the substrate supporting unit 10.

Note that the following method may be employed: the flexible substrate110 provided with a curved surface in advance is bonded to a plate-likemanufacturing substrate having rigidity with an adhesive which can beseparated so that the flexible substrate 110 is a plate-like stackedplate, and the light-emitting element 130 is formed on the stackedplate. When this method is used, the substrate supporting unit 10 candeal with the flexible substrate 110 like a plate-like substrate.

Each step in the method for manufacturing a light-emitting device of oneembodiment of the present invention is described below.

First Step

The flexible substrate 110 provided with a desired curved surface inadvance, which spontaneously deforms or returns into a shape having acurved surface, is supported in a flat plate-like shape along thesurface of the substrate supporting unit 10 (see FIGS. 2A and 2B).

Second Step

The light-emitting element 130 is formed in contact with the flexiblesubstrate 110 supported in a flat plate-like shape along the surface ofthe substrate supporting unit 10 (see FIG. 2C).

Note that the light-emitting element 130 includes a first electrode, asecond electrode, and a layer containing a light-emitting organiccompound therebetween. A structure of the light-emitting element 130 isdescribed in detail in Embodiment 5.

As a method for forming the light-emitting element 130, the followingmethod can be given, for example: one electrode is formed in contactwith the flexible substrate 110, a layer containing a light-emittingorganic compound is formed on the one electrode, and the other electrodeis stacked on the layer containing a light-emitting organic compound.

As another method, a method using a manufacturing substrate on a surfaceof which a layer capable of being separated from a layer which isstacked thereon is formed can be given.

Over the layer which is capable of being separated and formed over themanufacturing substrate, the one electrode is formed. The layercontaining a light-emitting organic compound is formed over the oneelectrode. The other electrode is stacked over the layer containing alight-emitting organic compound.

Next, the flexible substrate 110 prepared in a flat plate-like shape isattached to the other electrode side of the light-emitting element 130with an adhesive. Further, the light-emitting element 130 is separatedfrom the layer which is capable of being separated from a layer which isstacked thereon and formed over the manufacturing substrate, whereby thelight-emitting element 130 is transferred to the flexible substrate 110supported in a flat plate-like shape. The light-emitting element 130 maybe formed on the flexible substrate 110 by the above-described method.

Alternatively, a second flexible substrate is attached to the otherelectrode side of the light-emitting element 130 with an adhesive. Next,the light-emitting element 130 is separated from the layer which iscapable of being separated from a layer which is stacked thereon andformed over the manufacturing substrate, whereby the light-emittingelement 130 is transferred to the second substrate. Further, theflexible substrate 110 prepared in a flat plate-like shape is attachedto the one electrode side of the light-emitting element 130 with anadhesive. The light-emitting element 130 may be formed on the flexiblesubstrate 110 by the above-described method.

When the method in which the light-emitting element is formed over themanufacturing substrate on a surface of which the layer capable of beingseparated from a layer which is stacked thereon is formed is used, afilm which cannot be provided directly on the flexible substrate 110(e.g. a film which can be formed only at a temperature which exceeds theheat resistance of the flexible substrate 110) can be provided betweenthe flexible substrate 110 and the light-emitting element 130.

Specifically, a film which suppresses diffusion of an impurity into thelight-emitting element 130 (e.g. an oxide film or a nitride film,specifically, a silicon oxide film or a silicon nitride film) can beprovided between the light-emitting element 130 and a plastic film.

Further, a circuit, such as a wiring which supplies power to thelight-emitting element 130 or a transistor which drives thelight-emitting element 130, can be formed so as to overlap with thelayer capable of being separated from a layer which is stacked thereon.Thus, a circuit which cannot be provided directly on the flexiblesubstrate 110 can be provided between the substrate 110 and thelight-emitting element 130. For example, an active matrix light-emittingdevice (also referred to as active matrix display device) can bemanufactured over the flexible substrate 110.

The reliability of the light-emitting element 130 is lowered due to animpurity (e.g. water or oxygen) in some cases. A sealing film having agas barrier property and flexibility is preferably provided between theflexible substrate 110 and the light-emitting element 130 in order tosuppress diffusion of an impurity into the light-emitting element 130.

As the sealing film having a gas barrier property and flexibility, aglass plate, a metal foil, a plastic film where an inorganic film havinga gas barrier property is formed, or the like, each of which has athickness of several tens to several hundreds of micrometers, can begiven, for example. Note that the plastic film where an inorganic filmhaving a gas barrier property is formed can be formed in such a mannerthat a film which has a favorable gas barrier property and is formedover the layer which is capable of being separated from a layer which isstacked thereon and formed over the manufacturing substrate istransferred to a plastic film.

Third Step

The substrate supporting unit 10 is released from the flexible substrate110. The flexible substrate 110 provided with a desired curved surfacein advance spontaneously deforms or returns into a shape having a curvedsurface. As a result, the light-emitting region of the light-emittingelement 130 can be provided on a curved surface (see FIG. 2D).

Note that when the flexible substrate 110 which is deformed in a flatplate-like shape spontaneously returns into a shape having a curvedsurface, the surface of the substrate 110 stretches, and thus stress isapplied to the light-emitting element 130. In order to suppress stresswhich is to be applied to the light-emitting element 130, the thicknessof the flexible substrate 110 is preferably greater than or equal to 40μm and less than or equal to 300 μm. The curvature radius of the curvedsurface obtained in such a manner that the flexible substrate 110spontaneously returns is preferably greater than or equal to 20 mm.

In the case where the flexible substrate 110 spontaneously deforms orreturns so that the surface on which the light-emitting element 130 isformed has a concave shape, the compressive stress applied to a surfaceside of the light-emitting element 130 which is in contact with theflexible substrate 110 is larger than that applied to a surface side ofthe light-emitting element 130 which is not in contact with the flexiblesubstrate 110.

Further, in the case where the flexible substrate 110 spontaneouslydeforms or returns so that the surface on which the light-emittingelement 130 is formed has a convex shape, the tensile stress applied tothe surface side of the light-emitting element 130 which is in contactwith the flexible substrate 110 is larger than that applied to thesurface side of the light-emitting element 130 which is not in contactwith the flexible substrate 110.

As described above, although uneven stress is applied to thelight-emitting element 130, because the thickness of the light-emittingelement 130 is extremely small (for example, the thickness can beapproximately greater than or equal to 100 nm and less than or equal to600 nm), a difference in stress applied to the both surfaces of thelight-emitting element 130 is small. As a result, the light-emittingelement 130 is not easily damaged by spontaneous deformation or returnof the flexible substrate 110.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

Embodiment 2

In this embodiment, a method for manufacturing a light-emitting deviceof one embodiment of the present invention is described with referenceto FIG. 3 and FIGS. 4A to 4E. FIG. 3 illustrates a flowchart showing amethod for manufacturing a light-emitting device of one embodiment ofthe present invention, and FIGS. 4A to 4E are schematic views eachillustrating a structure of the light-emitting device in a manufacturingstep.

A method for manufacturing a light-emitting device 200 having alight-emitting region on a curved surface, which is exemplified in thisembodiment, is as follows.

In a first step, a light-emitting element 230 which includes a layercontaining a light-emitting organic compound between a pair ofelectrodes is formed in contact with a first substrate 210 which isflexible and supported in a flat plate-like shape (see (j1) in FIG. 3and FIG. 4A).

In a second step, a second substrate 220 having a heat shrink propertyis provided at a first temperature T1 with the first substrate 210interposed between the second substrate 220 and the light-emittingelement 230 (see (j2) in FIG. 3 and FIG. 4B). In other words, the secondsubstrate 220 is provided on a surface side of the first substrate 210where the light-emitting element 230 is not formed.

In a third step, the second substrate 220 is heated to a secondtemperature T2, whereby a light-emitting region of the light-emittingelement 230 is provided on a curved surface (see (j3) in FIG. 3 and FIG.4C).

Note that the substrate supporting unit 10 is used to support the firstsubstrate 210 in a flat plate-like shape.

The method for manufacturing the light-emitting device 200 exemplifiedin this embodiment includes a step of forming the light-emitting element230 on the first substrate 210 which is flexible and supported in a flatplate-like shape, and a step of providing the light-emitting region on acurved surface in such a manner that the second substrate 220 having aheat shrink property is attached to the first substrate 210 which isflexible and the attached second substrate 220 having a heat shrinkproperty is deformed. Thus, the light-emitting region of thelight-emitting element 230 can be provided on a curved surface withoutusing a shape-holding plate or the like and without another member beingin contact with the light-emitting element 230 for the deformation. As aresult, a method for manufacturing the lightweight light-emitting device200 having a light-emitting region on a curved surface can be provided.

A structure of the second substrate 220 having a heat shrink property,which can be used in the method for manufacturing the light-emittingdevice 200 of one embodiment of the present invention, is described.

The second substrate 220 having a heat shrink property shrinks whenheated from the first temperature T1 to the second temperature T2, andthus the size of the second substrate 220 is changed. For example, ashrink film (an uniaxially-stretched film, a biaxially-stretched film,or the like) can be used. In particular, an uniaxially-stretched film issuitable for formation of a developable surface because it can becontrolled so as to shrink in one direction.

As a material which can be applied to the second substrate 220 having aheat shrink property, a polyvinyl chloride film, a polypropylene film, apolyethylene film, a polystyrene film, a polyethylene terephthalatefilm, or a stacked film including a film selected from these films canbe given, for example. These films shrink by being heated to atemperature (e.g., about 80° C. to 120° C.) which is higher than roomtemperature. For example, the first temperature T1 can be roomtemperature and the second temperature T2 can be higher than roomtemperature.

Further, in the case where light emitted from the light-emitting element230 is extracted from the flexible first substrate 210 side where thesecond substrate 220 having a heat shrink property is attached, amaterial having a visible-light-transmitting property is used for thesecond substrate 220 having a heat shrink property, the flexible firstsubstrate 210, and an electrode of the light-emitting element 230 whichis placed on the flexible first substrate 210 side.

Each step in the method for manufacturing a light-emitting device of oneembodiment of the present invention is described below.

First Step

The light-emitting element 230 which includes the layer containing alight-emitting organic compound between the pair of electrodes is formedin contact with the first substrate 210 which is flexible and supportedin a flat plate-like shape by the substrate supporting unit 10 (see FIG.4A).

Second Step

The substrate supporting unit 10 is released from the first substrate210 provided with the light-emitting element 230. Next, the secondsubstrate 220 having a heat shrink property is provided at the firsttemperature T1 with the first substrate 210 interposed between thesecond substrate 220 and the light-emitting element 230 (see FIG. 4B).In other words, the second substrate 220 is provided on a surface sideof the first substrate 210 where the light-emitting element 230 is notformed.

Third Step

The second substrate 220 shrinks by being heated to the secondtemperature T2, so that the light-emitting region of the light-emittingelement 230 is provided on a curved surface (see FIG. 4C). Note that asa method for heating the substrate having a heat shrink property, amethod in which a heated gas is blown on the second substrate 220, amethod in which the substrate is transferred in a furnace filled with aheated gas, or the like can be given.

Modification Example

In a modification example of this embodiment, the method formanufacturing the light-emitting device 200 in which curved surfaces areselectively provided in the light-emitting region is described withreference to FIGS. 4D and 4E.

In the first step, the light-emitting element 230 which includes thelayer containing a light-emitting organic compound between the pair ofelectrodes is formed in contact with the first substrate 210 which isflexible and supported in a flat plate-like shape.

In the second step, a second substrate 220 a and a second substrate 220b, which have a heat shrink property, are selectively provided at thefirst temperature T1 with the first substrate 210 interposed between thesecond substrate 220 a and the light-emitting element 230 and betweenthe second substrate 220 b and the light-emitting element 230 (see FIG.4D).

In the third step, the second substrate 220 a and the second substrate220 b are heated to the second temperature T2, whereby part of thelight-emitting region of the light-emitting element 230 is provided onthe curved surfaces (see FIG. 4E).

The method for manufacturing the light-emitting device 200 exemplifiedin this embodiment includes a step of forming the light-emitting element230 on the first substrate 210 which is flexible and supported in a flatplate-like shape, and a step of providing the light-emitting region oncurved surfaces in such a manner that the second substrate 220 a and thesecond substrate 220 b, which have a heat shrink property and areselectively attached to the substrate 210, are deformed or returned.Thus, the curved surfaces can be provided on desired portions of thelight-emitting element 230 without using a shape-holding plate or thelike and without another member being in contact with the light-emittingelement 230 for the deformation. As a result, a method for manufacturingthe lightweight light-emitting device 200 having part of alight-emitting region on curved surfaces can be provided.

Note that arrows illustrated in FIG. 4D indicate directions in which thesecond substrate 220 a and the second substrate 220 b, which have a heatshrink property, shrink. The second substrates 220 a and 220 b having aheat shrink property are attached to the first substrate 210 so thatridge lines of the curved surfaces which are to be formed later arelocated at centerlines of the second substrate 220 a and 220 b. Thus,the curved surfaces can be provided on the desired portions.

Further, it is preferable to provide a terminal portion 280 a and aterminal portion 280 b which are electrically connected to thelight-emitting element 230 in portions of the light-emitting devicewhere the curved surface are not formed because the flexibility of theterminal portion is not lost. Thus, the terminal portion can be curvedto be connected to a connector or the like. The terminal portion formedin a plate-like portion can be easily connected to an external device,for example, a connector or a flexible printed circuit where a terminalis provided in a flat plate-like shape, as compared to a terminalportion formed in a portion where a curved surface is formed. Note thatwhen a terminal portion is provided for a portion where the curvedsurface is formed, the terminal portion can have rigidity.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

Embodiment 3

In this embodiment, a method for manufacturing a light-emitting deviceof one embodiment of the present invention is described with referenceto FIG. 5 and FIGS. 6A to 6E. FIG. 5 illustrates a flowchart showing amethod for manufacturing a light-emitting device of one embodiment ofthe present invention, and FIGS. 6A to 6E are schematic views eachillustrating a structure of the light-emitting device in a manufacturingstep.

A method for manufacturing a light-emitting device 300 having alight-emitting region on a curved surface, which is exemplified in thisembodiment, is as follows.

In a first step, a light-emitting element 330 which includes a layercontaining a light-emitting organic compound between a pair ofelectrodes is formed in contact with a first substrate 310 which isflexible and supported in a flat plate-like shape (see (k1) in FIG. 5and FIG. 6A).

In a second step, a second substrate 320 having a heat shrink propertyis provided at the first temperature T1 with the light-emitting element330 interposed between the first substrate 310 and the second substrate320 (see (k2) in FIG. 5 and FIG. 6B). In other words, the secondsubstrate 320 is provided on a surface side of the first substrate 310where the light-emitting element 330 is formed.

In a third step, the second substrate 320 is heated to the secondtemperature T2, whereby a light-emitting region of the light-emittingelement 330 is provided on a curved surface (see (k3) in FIG. 5 and FIG.6C).

Note that the substrate supporting unit 10 is used to support the firstsubstrate 310 in a flat plate-like shape.

The method for manufacturing the light-emitting device exemplified inthis embodiment includes a step of forming the light-emitting element330 on the first substrate 310 which is flexible and supported in a flatplate-like shape, and a step of providing the light-emitting region on acurved surface in such a manner that the second substrate 320 having aheat shrink property is attached to the first substrate 310 and isdeformed. Thus, the light-emitting region of the light-emitting element330 can be provided on a curved surface without using a shape-holdingplate or the like and without another member being in contact with thelight-emitting element 330 for the deformation. As a result, a methodfor manufacturing the lightweight light-emitting device having alight-emitting region on a curved surface can be provided.

A structure of the second substrate 320 having a heat shrink property,which can be used in the method for manufacturing the light-emittingdevice 300 of one embodiment of the present invention, can be similar tothat of the second substrate 220 having a heat shrink property, which isexemplified in Embodiment 2.

Note that in the case where light emitted from the light-emittingelement 330 is extracted from the second substrate 320 side having aheat shrink property is provided, a material having avisible-light-transmitting property is used for the second substrate 320having a heat shrink property and an electrode of the light-emittingelement 330 which is placed on the second substrate 320 side.

Each step in the method for manufacturing a light-emitting device of oneembodiment of the present invention is described below.

First Step

The light-emitting element 330 which includes the layer containing alight-emitting organic compound between the pair of electrodes is formedin contact with the first substrate 310 which is flexible and supportedin a flat plate-like shape by the substrate supporting unit 10 (see FIG.6A).

Second Step

The substrate supporting unit 10 is released from the first substrate310 provided with the light-emitting element 330. Next, the secondsubstrate 320 having a heat shrink property is provided at the firsttemperature T1 with the light-emitting element 330 interposed betweenthe first substrate 310 and the second substrate 320 (see FIG. 6B). Inother words, the second substrate 320 is provided on a surface side ofthe first substrate 310 where the light-emitting element 330 is formed.

Third Step

The second substrate 320 shrinks by being heated to the secondtemperature T2, so that the light-emitting region of the light-emittingelement 330 is provided on a curved surface (see FIG. 6C).

When the second substrate 320 having a heat shrink property shrinks, thesecond substrate 320 applies stress to a surface of the light-emittingelement 330 which is in contact with the second substrate 320. In thecase where the light-emitting element 330 is damaged by this stress, aprotection layer may be provided to overlap with the light-emittingelement 330 so that the stress is not applied directly to thelight-emitting element 330. In particular, a structure in which theprotection layer covering the light-emitting element 330 is fixed to thefirst substrate 310 is effective.

Alternatively, the following structure may be employed: thelight-emitting element 330 is formed over the first substrate 310provided with a partition, and the partition is attached to theprotection layer or the second substrate 320 having a heat shrinkproperty. The partition relieves stress generated when the secondsubstrate 320 having a heat shrink property shrinks, whereby thelight-emitting element 330 can be prevented from being damaged.

Note that as a material which can be used for the protection layer, aflexible film which is attached with an adhesive, a resin layer obtainedby application of a liquid material, or a film which can be formed by asputtering method or a chemical vapor deposition method can be given,for example.

Further, the second substrate 320 and/or the protection layer can alsoserve as a sealing film which suppresses diffusion of an impurity (e.g.,water or oxygen) into the light-emitting element 330.

Modification Example

In a modification example in this embodiment, the method formanufacturing the light-emitting device 300 in which convex curvedsurfaces and concave curved surfaces are selectively provided in thelight-emitting region is described with reference to FIGS. 6D and 6E.

In the first step, the light-emitting element 330 which includes thelayer containing a light-emitting organic compound between the pair ofelectrodes is formed in contact with the first substrate 310 which isflexible and supported in a flat plate-like shape.

In the second step, a second substrate 320 a and a second substrate 320b, which have a heat shrink property, are selectively provided at thefirst temperature T1 with the light-emitting element 330 interposedbetween the first substrate 310 and the second substrate 320 a andbetween the first substrate 310 and the second substrate 320 b. Further,a second substrate 320 c and a second substrate 320 d, which have a heatshrink property, are selectively provided with the first substrate 310interposed between the second substrate 320 c and the light-emittingelement 330 and between the second substrate 320 d and thelight-emitting element 330 (see FIG. 6D).

In the third step, the second substrates 320 a, 320 b, 320 c, and 320 dare heated to the second temperature T2, whereby part of thelight-emitting region of the light-emitting element 330 is provided oncurved surfaces (see FIG. 6E).

The method for manufacturing the light-emitting device 300 exemplifiedin this embodiment includes a step of forming the light-emitting element330 on the first substrate 310 which is flexible and supported in a flatplate-like shape and a step of providing part of the light-emittingregion on curved surfaces in such a manner that the second substrateshaving a heat shrink property which are selectively attached to thefirst substrate 310 are deformed. Thus, the curved surfaces can beprovided on the desired portions of the light-emitting element 330without using a shape-holding plate or the like and without anothermember being in contact with the light-emitting element 330 for thedeformation. As a result, a method for manufacturing the lightweightlight-emitting device 300 having part of a light-emitting region oncurved surfaces can be provided.

Note that arrows illustrated in FIG. 6D indicate directions in which thesecond substrates 320 a, 320 b, 320 c, and 320 d, which have a heatshrink property, shrink. The second substrates 320 a, 320 b, 320 c, and320 d having a heat shrink property are attached so that ridge lines ofthe curved surfaces which are to be formed later are located at thecenterlines of the second substrates 320 a, 320 b, 320 c, and 320 d.Thus, the curved surfaces can be provided on desired portions.

Further, the light-emitting device 300 can be folded to be compact insuch a manner that the convex curved surfaces and the concave curvedsurfaces overlap with each other by bend along dashed line A-B. Such alight-emitting device can be stored in a housing of a foldableinformation terminal device to be applied to a backlight of its displayportion. Alternatively, it can be applied to an active matrix displaydevice.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

Embodiment 4

In this embodiment, an example of a structure of a housing which canstore a light-emitting device formed by the method for manufacturing alight-emitting device of one embodiment of the present invention isdescribed with reference to FIG. 7 .

A housing 490 exemplified in this embodiment includes an exterior unit450, an outer lid 460, and an inner lid 455 which is between theexterior unit 450 and the outer lid 460. The inner lid 455 is attachedto the exterior unit 450 with an adhesive or sealing material (e.g. anO-ring), so that a sealed space is formed between the inner lid 455 andthe exterior unit 450.

A light-emitting device 400 manufactured by the manufacturing method ofone embodiment of the present invention is stored in the sealed spaceformed between the inner lid 455 and the exterior unit 450 so that alight-emitting region of the light-emitting device 400 faces theexterior unit 450 side.

The inner lid 455 and the exterior unit 450 are each formed using amaterial which suppresses entry of an impurity (e.g., water or oxygen).With such a structure, reliability of the light-emitting device 400stored in the sealed space can be prevented from being reduced becauseof contamination of the light-emitting device 400 due to an impurity.

An example of a material which can be used for the inner lid 455 and theexterior unit 450 is, in addition to a dense inorganic material such asmetal, glass, or a ceramics plate, plastic modified with a layer whichsuppresses entry of an impurity (specifically, a layer containing thedense inorganic material or a layer containing diamond-like carbon,silicon oxide, silicon nitride, or the like).

Note that a material which captures an impurity (e.g., a desiccant or adeoxidant) may be stored in the sealed space formed between the innerlid 455 and the exterior unit 450. A circuit 453 or the like for drivingthe light-emitting device 400 may also be stored to be electricallyconnected to a terminal portion 480 of the light-emitting device 400.

Note that the light-emitting device 400 has a light-emitting region on acurved surface, and a character and an image can be displayed in thelight-emitting region. The exterior unit 450 has a light-transmittingregion in a position which overlaps with the light-emitting device 400,and thus a user can perceive the displayed character and image from theoutside of the exterior unit 450. A display portion reaches a sidesurface of the housing, so that a large amount of data can be displayed.

Further, another space may be provided between the inner lid 455 and theouter lid 460 in addition to the sealed space formed between the innerlid 455 and the exterior unit 450. The housing 490 exemplified in thisembodiment includes a secondary battery 457 in the space formed betweenthe inner lid 455 and the outer lid 460. As described above, when acomponent which needs maintenance or inspection is placed in the spacewhich is not the sealed space, the frequency of contamination of thesealed space due to an impurity can be reduced.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

Embodiment 5

In this embodiment, examples of a structure of a light-emitting elementwhich is formed by the method for manufacturing a light-emitting deviceof one embodiment of the present invention so as to be in contact with asubstrate supported in a flat plate-like shape are described withreference to FIGS. 8A to 8E.

The light-emitting element described in this embodiment includes a firstelectrode, a second electrode, and a layer containing a light-emittingorganic compound (hereinafter referred to as EL layer) between the firstelectrode and the second electrode. One of the first electrode and thesecond electrode serves as an anode and the other serves as a cathode. Astructure of the EL layer is selected as appropriate depending on thepolarities and materials of the first electrode and the secondelectrode.

Note that at least one of the first electrode and the second electrodeis formed using a conductive film which transmits visible light.

As the conductive film which transmits visible light, for example, anindium tin oxide film, or a metal thin film which transmits light (e.g.,a thin film with a thickness of approximately greater than or equal to 5nm and less than or equal to 30 nm) can be used.

Structure Example 1 of Light-Emitting Element

An example of the structure of the light-emitting element is illustratedin FIG. 8A. In the light-emitting element illustrated in FIG. 8A, an ELlayer is provided between an anode 1101 and a cathode 1102.

When voltage higher than the threshold voltage of the light-emittingelement is applied between the anode 1101 and the cathode 1102, holesare injected to the EL layer from the anode 1101 side and electrons areinjected to the EL layer from the cathode 1102 side. The injectedelectrons and holes are recombined in the EL layer, so that alight-emitting substance contained in the EL layer emits light.

In this specification, a layer or a stacked body which includes oneregion where electrons and holes injected from both ends are recombinedis referred to as a light-emitting unit. That is, the light-emittingelement illustrated in FIG. 8A as Structure Example 1 of alight-emitting element includes one light-emitting unit.

A light-emitting unit 1103 may include at least one light-emitting layerincluding a light-emitting substance, and may have a structure in whichthe light-emitting layer and a layer other than the light-emitting layerare stacked. Examples of the layer other than the light-emitting layerare layers containing a substance having a high hole-injection property,a substance having a high hole-transport property, a substance having apoor hole-transport property (substance which blocks holes), a substancehaving a high electron-transport property, a substance having a highelectron-injection property, and a substance having a bipolar property(substance having high electron- and hole-transport properties). Inparticular, the layer which contains a substance having a highhole-injection property and is provided in contact with the anode andthe layer which contains a substance having a high electron-injectionproperty and is provided in contact with the cathode reduce a barrier ofcarrier injection from the electrodes to the light-emitting unit. Theselayers can be each referred to as a carrier injection layer.

An example of a specific configuration of the light-emitting unit 1103is illustrated in FIG. 8B. In the light-emitting unit 1103 illustratedin FIG. 8B, a hole-injection layer 1113, a hole-transport layer 1114, alight-emitting layer 1115, an electron-transport layer 1116, and anelectron-injection layer 1117 are stacked in this order from the anode1101 side.

Structure Example 2 of Light-Emitting Element

Another example of the structure of the light-emitting element isillustrated in FIG. 8C. In the light-emitting element illustrated inFIG. 8C, the EL layer including the light-emitting unit 1103 is providedbetween the anode 1101 and the cathode 1102. Further, an intermediatelayer 1104 is provided between the cathode 1102 and the light-emittingunit 1103. Note that a structure similar to that of the light-emittingunit included in Structure Example 1 of the light-emitting element,which is described above, can be applied to the light-emitting unit 1103in Structure Example 2 of the light-emitting element and that thedescription of Structure Example 1 of the light-emitting element can bereferred to for the details.

The intermediate layer 1104 includes at least a charge generationregion. For example, a structure can be employed in which a first chargegeneration region 1104 c, an electron-relay layer 1104 b, and anelectron-injection buffer 1104 a are stacked in that order from thecathode 1102 side.

The behaviors of electrons and holes in the intermediate layer 1104 aredescribed. When a voltage higher than the threshold voltage of thelight-emitting element is applied between the anode 1101 and the cathode1102, holes and electrons are produced in the first charge generationregion 1104 c, and the holes move into the cathode 1102 and theelectrons move into the electron-relay layer 1104 b.

The electron-relay layer 1104 b has a high electron-transport propertyand immediately transfers the electrons generated in the first chargegeneration region 1104 c to the electron-injection buffer 1104 a. Theelectron-injection buffer 1104 a reduces a barrier which hindersinjection of the electrons into the light-emitting unit 1103.

In addition, the electron-relay layer 1104 b can prevent, for example,interaction in which the substance included in the first chargegeneration region 1104 c and the substance included in theelectron-injection buffer 1104 a are in contact with each other at theinterface between the electron-injection buffer 1104 a and the firstcharge generation region 1104 c and the functions of the first chargegeneration region 1104 c and the electron-injection buffer 1104 a aredamaged.

The range of choices of materials that can be used for the cathode inStructure Example 2 of the light-emitting element is wider than that ofmaterials that can be used for the cathode in Structure Example 1 of thelight-emitting element. This is because a material having a relativelyhigh work function can be used for the cathode in Structure Example 2 aslong as the cathode in Structure Example 2 receives at least holesgenerated by the intermediate layer.

Structure Example 3 of Light-Emitting Element

Another example of the structure of the light-emitting element isillustrated in FIG. 8D. In the light-emitting element illustrated inFIG. 8D, an EL layer including two light-emitting units is providedbetween the anode 1101 and the cathode 1102. Furthermore, theintermediate layer 1104 is provided between a first light-emitting unit1103 a and a second light-emitting unit 1103 b.

Note that the number of the light-emitting units provided between theanode and the cathode is not limited to two. A light-emitting elementillustrated in FIG. 8E has what is called a tandem structure in which nlight-emitting units 1103 (n is a natural number of two or more) areincluded. Note that the intermediate layer 1104 is provided between thestacked light-emitting units.

A structure which is similar to the structure of the light-emitting unit1103 in Structure Example 1 of the light-emitting element can be appliedto the light-emitting unit 1103 in Structure Example 3 of thelight-emitting element. Further, a structure which is similar to that ofthe intermediate layer 1104 in Structure Example 2 of the light-emittingelement can be applied to the intermediate layer 1104 in StructureExample 3 of the light-emitting element.

When voltage higher than the threshold voltage of the light-emittingelement is applied between the anode 1101 and the cathode 1102, holesand electrons are generated in the intermediate layer 1104, and theholes move into the light-emitting unit provided on the cathode 1102side and the electrons move into the light-emitting unit provided on theanode side.

The holes injected into the light-emitting unit provided on the cathodeside are recombined with the electrons injected from the cathode side,so that a light-emitting substance contained in the light-emitting unitemits light. Thus, the holes and electrons generated in the intermediatelayer 1104 cause light emission in the respective light-emitting units.

Note that the light-emitting units can be provided in contact with eachother when these light-emitting units allow the same structure as theintermediate layer to be formed therebetween. Specifically, when onesurface of the light-emitting unit is provided with a charge generationregion, the charge generation region functions as a first chargegeneration region of the intermediate layer; thus, the light-emittingunits can be provided in contact with each other.

Note that an interlayer can be provided between the cathode and the n-thlight-emitting unit.

Light can be obtained from a light-emitting organic compound containedin the light-emitting unit of any of the above-described light-emittingelements, and the emission color can be selected by changing the type ofthe light-emitting organic compound.

Further, a plurality of light-emitting materials which emits light ofdifferent colors are used, whereby the width of the emission spectrumcan be expanded.

Note that in order to obtain white light emission, for example, astructure may be employed in which at least two layers containinglight-emitting substances are provided so that light of complementarycolors is emitted. Specific examples of complementary colors include“blue and yellow”, “blue-green and red”, and the like.

Further, in order to obtain white light emission with an excellent colorrendering property, an emission spectrum preferably spreads through theentire visible light region. For example, a light-emitting element mayinclude layers emitting light of blue, green, and red.

Method of Manufacturing Light-Emitting Element

A method for manufacturing the light-emitting element will be described.Over the first electrode, the layers described above are combined asappropriate to form an EL layer. Any of a variety of methods (e.g., adry process or a wet process) can be used to form the EL layer dependingon the material for the EL layer. For example, a vacuum evaporationmethod, an inkjet method, a spin coating method, or the like may beselected. Note that a different formation method may be employed foreach layer. The second electrode is formed over the EL layer, so thatthe light-emitting element is manufactured.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

Embodiment 6

In this embodiment, electronic devices and lighting devices, each ofwhich includes a light-emitting device formed by the method formanufacturing a light-emitting device of one embodiment of the presentinvention, are described with reference to FIGS. 9A to 9E.

FIG. 9A illustrates an example of a cellular phone. The cellular phone7400 is provided with a display portion 7402 incorporated in a housing7401, operation buttons 7403, an external connection port 7404, aspeaker 7405, a microphone 7406, and the like. Note that the cellularphone 7400 is manufactured using a light-emitting device for the displayportion 7402.

When the display portion 7402 of the cellular phone 7400 illustrated inFIG. 9A is touched with a finger or the like, data can be input into thecellular phone 7400. Further, operations such as making a call andinputting a letter can be performed by touch on the display portion 7402with a finger or the like.

With the operation buttons 7403, power ON or OFF can be switched. Inaddition, a variety of images displayed on the display portion 7402 canbe switched; switching a mail creation screen to a main menu screen, forexample.

Here, the display portion 7402 includes a light-emitting devicemanufactured by the method of one embodiment of the present invention.Thus, the mobile phone can have a curved display portion and highreliability.

FIG. 9B is an example of a wristband-type display device. A portabledisplay device 7100 includes a housing 7101, a display portion 7102, anoperation button 7103, and a sending and receiving device 7104.

The portable display device 7100 can receive a video signal with thesending and receiving device 7104 and can display the received video onthe display portion 7102. In addition, with the sending and receivingdevice 7104, the portable display device 7100 can send an audio signalto another receiving device.

With the operation button 7103, power ON/OFF, switching displayedvideos, adjusting volume, and the like can be performed.

Here, the display portion 7102 includes a light-emitting devicemanufactured by the method of one embodiment of the present invention.Thus, the mobile display device can have a curved display portion andhigh reliability.

FIGS. 9C to 9E each illustrate an example of a lighting device. Lightingdevices 7200, 7210, and 7220 each include a stage 7201 provided with anoperation switch 7203 and a light-emitting portion supported by thestage 7201.

The lighting device 7200 illustrated in FIG. 9C includes alight-emitting portion 7202 having a wave-shaped light-emitting surface,which is good-design lighting device.

A light-emitting portion 7212 included in the lighting device 7210illustrated in FIG. 9D has two convex-curved light-emitting portionssymmetrically placed. Thus, all directions can be illuminated with thelighting device 7210 as a center.

The lighting device 7220 illustrated in FIG. 9E includes aconcave-curved light-emitting portion 7222. This is suitable forilluminating a specific range because light emitted from thelight-emitting portion 7222 is collected to the front of the lightingdevice 7220.

The light-emitting portion included in each of the lighting devices7200, 7210, and 7220 are flexible; thus, the light-emitting portion maybe fixed on a plastic member, a movable frame, or the like so that anemission surface of the light-emitting portion can be bent freelydepending on the intended use.

Note that although the lighting device in which the light-emittingportion is supported by the stage is described as an example here, ahousing provided with a light-emitting portion can be fixed on a ceilingor suspended from a ceiling. Since the light-emitting surface can becurved, the light-emitting surface is curved to have a concave shape,whereby a particular region can be brightly illuminated, or thelight-emitting surface is curved to have a convex shape, whereby a wholeroom can be brightly illuminated.

This embodiment can be implemented in combination with any of the otherembodiments in this specification as appropriate.

REFERENCE NUMERALS

10: substrate supporting unit, 100: light-emitting device, 110:substrate, 130: light-emitting element, 200: light-emitting device, 210:substrate, 220: substrate, 220 a: substrate, 220 b: substrate, 230:light-emitting element, 280 a: terminal portion, 280 b: terminalportion, 300: light-emitting device, 310: substrate, 320: substrate, 320a: substrate, 320 b: substrate, 320 c: substrate, 320 d: substrate, 330:light-emitting element, 400: light-emitting device, 450: exterior unit,453: circuit, 455: inner lid, 457: secondary battery, 460: outer lid,480: terminal portion, 490: housing, 1101: anode, 1102: cathode, 1103:light-emitting unit, 1103 a: light-emitting unit, 1103 b: light-emittingunit, 1104: intermediate layer, 1104 a: electron-injection buffer, 1104c: charge generation region, 1113: hole-injection layer, 1114:hole-transport layer, 1115: light-emitting layer, 1116:electron-transport layer, 1117: electron-injection layer, 7100: portabledisplay device, 7101: housing, 7102: display portion, 7103: operationbutton, 7104: sending and receiving device, 7200: lighting device, 7201:stage, 7202: light-emitting portion, 7203: operation switch, 7210:lighting device, 7212: light-emitting portion, 7220: lighting device,7222: light-emitting portion, 7400: cellular phone, 7401: housing, 7402:display portion, 7403: operation button, 7404: external connection port,7405: speaker, 7406: microphone.

This application is based on Japanese Patent Application Serial No.2012-178810 filed with Japan Patent Office on Aug. 10, 2012, the entirecontents of which are hereby incorporated by reference.

The invention claimed is:
 1. A semiconductor device comprising: anexterior unit comprising glass; a light-emitting panel over the exteriorunit; a circuit for driving the light-emitting panel over thelight-emitting panel; a metal plate over the light-emitting panel; anadhesive bonding the metal plate to the exterior unit; a secondarybattery over the metal plate; and an outer lid over the secondarybattery, wherein the outer lid overlaps with the metal plate without thesecondary battery provided therebetween, wherein the light-emittingpanel comprises a light-emitting element over a first substrate, thefirst substrate being flexible; wherein the light-emitting panelcomprises a curved edge portion, wherein a terminal portion is providedon a portion of the curved edge portion which is not bent, wherein theterminal portion is electrically connected to the circuit, wherein theterminal portion faces the light-emitting panel, wherein the metal platecomprises a region not overlapping with the circuit, and wherein thesecondary battery does not overlap with the terminal portion.
 2. Thesemiconductor device according to claim 1, further comprising: aflexible printed circuit.
 3. The semiconductor device according to claim2, wherein the terminal portion is provided on the portion of the curvededge portion which is not bent, and wherein the terminal portion iselectrically connected to the circuit.
 4. A semiconductor devicecomprising: a glass plate; a display panel over the glass plate; acircuit for driving the display panel over the display panel; a metalplate over the display panel; an adhesive bonding the metal plate to theglass plate; and a secondary battery over the metal plate andoverlapping with the display panel, wherein the display panel comprisesa light-emitting element over a first substrate, the first substratebeing flexible, wherein the display panel comprises a curved edgeportion, wherein a terminal portion is provided on a portion of thecurved edge portion which is not bent, wherein the terminal portion iselectrically connected to the circuit, wherein the metal plate comprisesa region not overlapping with the circuit, and wherein the secondarybattery does not overlap with the terminal portion.
 5. The semiconductordevice according to claim 4, further comprising: a flexible printedcircuit.
 6. The semiconductor device according to claim 5, wherein theterminal portion is provided on the portion of the curved edge portionwhich is not bent, and wherein the terminal portion is electricallyconnected to the circuit.
 7. A semiconductor device comprising: anexterior unit; a light-emitting panel over the exterior unit; a circuitover the light-emitting panel; a layer comprising a metal over thecircuit; a secondary battery over the layer comprising a metal; and afirst lid over the secondary battery, wherein each of the light-emittingpanel and the circuit is provided in a first space formed between theexterior unit and the layer comprising a metal, wherein the secondarybattery is provided in a second space formed between the layercomprising a metal and the first lid, wherein a light-emitting region ofthe light-emitting panel comprises a curved edge portion, and whereinthe light-emitting panel comprises a curved edge portion on which aterminal portion is provided.
 8. The semiconductor device according toclaim 7, further comprising: a flexible printed circuit.